Roger Federer won the battle of tennis giants during his mixed-doubles meeting with Serena Williams at the Hopman Cup, but both players were beaming with smiles after the match was over.

"It was a great experience. I'm kinda sad it's over. I was just warming up!" laughed Williams after the match, in which Swiss pair Federer and Belinda Bencic over came Williams and her partner Frances Tiafoe.

"It was so fun... we grew up together, really. After all these years, we've actually never done this, so it was super cool that we get to do it at such a pivotal point in both our careers," Williams added.

"For me, it was super cool. I wanted to take pictures and I wanted bring my baby out. I was way too excited!"

Williams was gushing in her praise, saying: "This guy is great. He's the greatest of all time, to be honest.

"Both on the court and off the court has such charisma and he's such a wonderful player.

"I think his serve is super-underestimated. He has a killer serve, - literally, you can’t read it. There's a reason why he's a greatest because you can't be that great and not have such an awesome weapon like that serve.

"I watched him all the time and I never knew how amazing it was. Hopefully, I can get some tips later!"

The pair took selfies after the matchup and posed for photos for the fans. Federer captioned his "Oh what a night," while Williams wrote: "The GOAT vs the GOAT. The GOAT won."

But, as one tennis correspondent noted, it was tinged with a little sadness with the knowledge that the competition that brought them together, the Hopman Cup, was being moved aside, with funding being diverted to stage ATP World Team Cup in Australia instead.

Much publicity for the big mixed doubles match pitting Serena Williams and Roger Federer against each other for the first time. Shame then that the Hopman Cup is set to disappear next year. A rare opportunity in tennis for men & women to team up with each other for their country.